1. Field of the Invention
The present invention relates to an endoscope system for imaging an observation target in a subject, an operation method for an endoscope system, a processor device, and an operation method for a processor device.
2. Description of the Related Art
In the medical field, it is common to perform diagnosis by observing an image obtained by imaging an observation target (mucous membrane of the digestive tract or the like) in a subject using an endoscope system. The endoscope system includes a light source device that generates illumination light for irradiating an observation target, an endoscope that has an insertion unit inserted into the subject and images the observation target with an image sensor provided at the distal end of the insertion unit, and a processor device that generates an image of the observation target based on an image signal output from the image sensor and displays the image on a monitor. The endoscope system sequentially displays images of the observation target in real time on the monitor. That is, in the endoscope system, a video of the observation target is displayed on the monitor. A doctor performs diagnosis while observing the video displayed on the monitor.
In addition, the endoscope system includes a freeze button for inputting an instruction to acquire a still image of the observation target. When the freeze button is pressed, the endoscope system acquires a still image of the observation target and stores the still image as a record of observation or the like in a storage unit (for example, a non-volatile memory) provided in the processor device, for example. In addition, an endoscope system including an imaging optical system allowing a zoom operation is known. In recent years, an endoscope system is known that, when acquiring a still image in response to the pressing of the freeze button, a part of the acquired still image is enlarged based on the imaging magnification determined by the zoom operation and is displayed on the monitor together with a video of the observation target so that diagnosis can be easily performed in real time (refer to JP2013-240522A).